The intended objects for the loop formation according to this invention include metallic binding bands. Metallic binding bands are formed as illustrated in FIGS. 7 and 8.
A metallic binding band 1 is composed of a binding section 2 wherein a band-shaped steel material cut to a prescribed length has been formed in a ring, a lever 3 wherein a band-shaped steel material of a prescribed length has been welded to the connected overlapping ends 2a of the binding section 2 and formed in a curved shape, and a retaining piece 4 for fixing the lever 3 wherein a band-shaped steel material cut to a prescribed length has been bent into the shape of a U and welded to a prescribed position on the binding section 2, with both ends bending around the outside of the ring formed by the binding section 2.
The metallic binding band 1 is prepared by cutting the binding section 2, lever 3, and retaining piece 4 separately out of a long steel material, processing them appropriately, welding the retaining piece 4 onto the binding section 2, and welding the lever 3 to the overlapped section 2a of both ends of the binding section 2.
However, this method results in a problem that, in welding the lever 3 to the overlapped section 2a of the binding section 2, as shown in FIG. 9, the binding section 2 is flattened or the lever 3 is left flat or deformed from its initial arc curve. It follows that some difficulty is experienced in inserting a hose into the binding section 2 and that force is partially applied in clamping, resulting in deterioration of the hose.
There is sometimes a flash at the end section of the connection side of the lever 3 to the binding section 2. In the presence of such a flash at the end 3a of the lever 3, when the lever 3 is turned over (clamped) about the end 3a of the connecting side of the lever 3 to the binding section 2, there is a possibility that clamping the lever 3 will result in the binding section 2 being cut by the flash at the end 3a of the lever 3.
For these reasons, it has become necessary to after-treat the formed metallic binding band to make the binding section 2 exactly circular and to form the lever 3 into an arc.